A unit is only in cover when they are in contact with the cover.
A unit is only protected by cover from an attacker if the cover is between the unit and said attacker and the cover obscures some of the line-of-sight of the attacker to the unit.
For example, if an attacker is in an elevated position over a target, they may well be able to draw a line-of-sight over cover to all of a target, meaning the target is unprotected by that cover.
The Acolyte is not close enough to the wall to be in cover but it does obscure nearly half of him from Guardian A, so he has the protection of low cover from an attack from Guardian A.
In their elevated position, Guardian B can see practically all of the Acolyte, so the wall does not provide protection to the Acolyte from attacks by Guardian B.
VERY LOW COVER
Any cover that almost completely obscures a typical adult human lying down is very low cover. On the game table, that's a quarter the height of a LEGO mini-figure (or one brick high).
Any cover that obscures a typical standing adult human from the waist down is low cover. On the game table, that's half the height of a LEGO mini-figure (or two bricks high).
Any cover that obscures a typical standing adult human from the shoulders down is high cover. On the game table, that's any cover that a LEGO mini-figure's head still pokes above (that's 3 or 4 bricks high).
Any cover that a typical standing human adult is completely obscured by but that can be peeked around by said human who is behind it, is corner cover.
In this example, Guardian A is in corner cover from the Cybercop, Guardian B and D are in high cover and Guardian C is in low cover.
Cover also has a Defence stat, which should be agreed by the players when setting up the cover for a game.
Soft cover, such as wooden fences and bushes should be around DE 3. Hard cover, such as brick walls would be around DE 12. Very hard cover, such as a thick concrete wall would be around DE 18.
From left to right:
There's no penalty to the roll-to-hit when attacking cover. So sometimes it's a good tactic to attack the cover that a unit is in rather than the unit itself.
Attacker B rolls to hit successfully with an attack that does 2D6 damage. Attacker B rolls 9 damage. That's greater than the DE of the cover, which is therefore penetrated with 6 damage. Unit A has a DE of 5, so Unit A is going to be wounded by the remaining damage. See Wounds & Injuries.
When cover is attacked, any penetrating damage also causes wounds directly to a section of cover.
Example: A fence with DE 3 is hit with 13 damage. That's 10 damage that penetrates and therefore three wounds to the fence. 3D6 are rolled, and any result of 6 on those three D6 means that section of fence is destroyed.
A moving foot-unit or mech can vault over very low or low cover without it affecting the distance they move.
High cover can also be vaulted by a foot-unit or mech, but this requires 6" of the unit's move.
Mechs, heavier vehicles and particularly strong foot-units may find it easier to just pile through high cover rather than vault it.
PILING THROUGH COVER
To pile through cover, on contact with the cover a moving unit rolls a D6 and adds their ST.
If a foot-unit that fails to pile through cover is running or sprinting, they must pass a DE test or fall prone and be stunned.
Mechs Failing to Pile Through Cover
If a mech that fails to pile through cover is running or sprinting, they must pass an RE test or fall prone.
Vehicles Failing to Pile Through Cover
If a vehicle fails to pile through cover that is rushing or flat-out, it automatically crashes. See Vehicles.
CLOSE COMBAT OVER COVER
It is possible for two units opposite each other that are in contact with cover to engage in close combat over cover, as if they were in base-to-base contact with each other.
All rolls to hit are with a -1 penalty. All dodge/parry attempts are with a +1 bonus.
All the units are in contact with the cover. However, Guardian A is not opposite either Cybercop A or Cybercop B so can't engage in close combat. Cybercop A can't engage in close combat with Guardian A either.
CyberCop B can engage in close combat with Guardian B and C, and vice versa, since they're opposite each other.
When a unit is in cover and is being attacked from a direction where they cannot dive into cover or dive to prone out of line-of-sight of an attack they are flanked.
A flanked unit suffers a -2 penalty to any dive to prone that they attempt to avoid an attack from an enemy unit that is flanking them.
A unit can dive over low cover or around a corner and if they can do this they are not considered flanked. If another unit is in the way of where a diving unit will land, that unit can be moved enough to make room for the diving unit.
In the example above, Guardian D is flanked by Cybercop B because they cannot dive into cover or out of line-of-sight of Cybercop B. Guardian D is not flanked by Cybercop A as they can dive to prone to their right, taking them out of Cybercop A's line-of-sight.
Guardian A is not flanked by Cybercop B as they can dive around the corner on their right. If Guardian A could dive over the wall behind (they can't, it's high cover), Guardian B would be moved to make room for them. Guardian C just wanted to photo-bomb this example.